Abstract: An image-forming apparatus includes a main body divided into a first part and a second part, an imaging unit, and a detecting device. The first part is pivotably provided to the second part to open the apparatus. The imaging unit is detachably mounted in a predetermined station of the first part. The detecting device detects whether an image forming operation can be executed or not, and is actuated only when the first part is closed to the second part with the presence of the imaging unit in the predetermined station of the first part.

Abstract: An image forming system for copiers, printers and the like having a main body which forms images on sheets of paper inserted therein and a plurality of sheet feeding units selectively attachable to the main body. The main body has a timing roller set which transports the papers to an image forming position with an appropriate timing, and each of the sheet feeding units has a paper feeding system with a take-up roller for supplying papers from the unit directly to the timing roller set without intermediate rollers in the main body. The system further includes side and bottom sheet feeding units selectively attachable to the main body and the side unit includes a guide for guiding sheets from the bottom unit into the main body. The system further includes a separate sheet guide mountable on the bottom unit for guiding sheets into the main body when the side unit is absent from the system.

Abstract: An image forming apparatus comprising a laser beam radiating unit utilized as a light source, and an optical system that the surface of an original reflects a laser beam radiated from the radiating unit to project an image reflected from the original onto a photosensitive member. In this apparatus, an image is formed selectively in a print mode so that an image results from turning on and off the laser beam, in a copy mode that a copy of an original results from exposure of the photosensitive member to the laser beam reflected from the surface of an original or in a composite mode that a composite image is formed of a copy of an original and an image resulting from turning on and off the laser beam. Further, this apparatus comprises a projection lens unit for projecting an image reflected from an original onto the photosensitive member.

Abstract: An image-forming apparatus includes: a first unit; a second unit opening and closing with respect to the first unit; an image-forming unit having a photosensitive member, a developing device, and a housing surrounding them; a holding device detachably holding the image-forming unit and attached to the second unit to move between a first and second positions; and an eraser device arranged at the second unit. The housing has a hole for connecting with an outer surface of the member. The eraser device is positioned outside the hole of the housing when the holding device is at the first position in opening the second unit, and in the hole thereof when the holding device is at the second position is closing the second unit. A method, in the apparatus, includes a first unit and a second unit opening and closing with respect to the first unit.

Abstract: An image forming apparatus comprising a laser beam radiating unit utilized as a light source, and an optical system that the surface of an original reflects a laser beam radiated from the radiating unit to project an image reflected form the original onto a photosensitive member. In this apparatus, an image is formed selectively in a print mode that an image results from turning on and off the laser beam, in a copy made that a copy of an original results form exposure of the photosensitive member to the laser beam reflected from the surface of an original or in a composite mode that a composite image is formed of a copy of an original and an image resulting from turning on and off the laser beam. Also, this apparatus comprises a reflecting member which is provided on an original supporting table and extends in the sub scanning direction, and a sensor for detecting the laser beam reflected from the reflecting member.

Abstract: An image forming apparatus includes a laser beam radiating unit utilized as a light source, and an optical system that the surface of an original reflects a laser beam radiated from the radiating unit to project an image reflected from the original onto a photosensitive member. In this apparatus, an image is formed selectively in a print mode that an image results from turning on and off the laser beam, in a copy mode that a copy of an original results from exposure of the photosensitive member to the laser beam reflected from the surface of an original or in a composite mode that a composite image is formed of a copy of an original and an image resulting from turning on and off the laser beam. Also, this apparatus comprises a reflector for directing the laser beam to the photosensitive member, and the reflector is automatically set at the reflecting position when the original cover is open or the print mode is selected.

Abstract: A laser beam scanning apparatus for beam scanning a medium with the laser beam being deflected by a deflector, comprising a first mirror provided for reflecting the laser beam after deflected by the deflector and a second mirror provided for folding a light path between the first mirror and the medium in such a relationship that a first light path between the deflector and the first mirror is not intersected with a second light path between the second mirror and the medium. The first and second mirrors are arranged so as to be movable in parallel respectively for adjusting a length of scanning line on the recording medium, wherein either one of the first and second mirrors is moved when adjusting and said moved mirror has a lesser shift amount of the scanning line on the recording medium in a direction perpendicular to the scanning line as compared with the other mirror.

Abstract: A laser scanning optical system including a rotatable polygonal mirror for scanning the photosensitive surface with the laser beam in a scanning direction, a lens unit for converging the laser beam reflected by the polygonal mirror on the photosensitive surface, a first reflection mirror for reflecting the laser beam passed though the lens unit to the photosensitive surface, a second reflection mirror for reflecting the laser beam reflected by a part of the first reflection mirror, a sensor arranged to receive the laser beam which is reflected by the second reflection mirror and has passed through a specific position equivalent to the photosensitive surface for generating a synchronizing signal for commanding start of modulation of the laser beam, and first and second lens elements both interposed between the specific position and the sensor so as to keep a conjugate condition therebetween.

Abstract: An apparatus provided with a first reflector for reflecting a light beam deflected by a deflector in a light beam scanning apparatus and a second reflector for directing the light beam from the first reflector toward an image forming point after contacting again the first reflector. The light beam is reciprocated between the first and second reflectors thereby forming a light path of two times the space that they are disposed. A deflector is disposed on a side of the light path extending from the first reflector to the light beam image forming point together with a light beam emitting source which irradiate the light beam on the same level of the light path and make the light path length at both ends of the light beam scanning range equal to each other by arranging an angle between the first and second reflectors.

Abstract: An image forming apparatus comprising a laser beam radiating unit utilized as a light source, and an optical system that the surface of an original reflects a laser beam radiated from the radiating unit to project a image reflected from the original onto a photosensitive member. In this apparatus, an image is formed selectively in a print mode that an image results from turning on and off the laser beam, in a copy mode that a copy of an original results from exposure of the photosensitive member to the laser beam reflected from the surface of an original or in a composite mode that a composite image is formed of a copy of an original and an image resulting from turning on and off the laser beam. Further, this apparatus comprises a transporting unit for transporting a sheet on which a latent image formed on the photosensitive member is transferred onto the original glass, so that a sheet once discharged from the main body can be reused as an original.

Abstract: An image-forming apparatus comprises a machine body and a paper discharge unit removably attached to the machine body. The machine body defines a face-down discharge tray on top. The paper discharge unit includes a face-up discharge tray and a discharge roller pair. A switch lever is provided in the machine body for selecting between a state in which recording paper is turned over for discharge onto the face-down discharge tray, and a second state in which the recording paper is discharged face up onto the face-up discharge tray.

Abstract: An image forming apparatus comprising a laser beam radiating unit utilized as a light source, and an optical system that the surface of an original reflects a laser beam radiated from the radiating unit to project an image reflected from the original onto a photosensitive member. In this apparatus, an image is formed selectively in a print mode that an image results from turning on and off the laser beam, in a copy mode that a copy of an original results from exposure of the photosensitive member to the laser beam reflected from the surface of an original or in a composite mode that a composite image is formed of a copy of an original and an image resulting from turning on and off the laser beam. Further, this apparatus comprises a sensor for receiving the laser beam reflected from the surface of an original, and the image of an original and composite image are read by the sensor.

Abstract: A laser beam scanning apparatus comprises a first mirror provided for reflecting a light path between a deflector and recording medium, a beam detecting sensor for determining a start position for recording by the beam on the recording medium, and a second mirror for guiding the beam reflected by the first mirror to the sensor. The second mirror is arranged such that the beam from the first mirror is guided to the sensor after it is reflected at least one time by said first mirror. In addition, the second mirror is arranged such that on the equation .theta..sub.2 =2.theta..sub.1 is satisfied where .theta..sub.1 and .theta..sub.2 respectively denote the inclination of the first and the second mirrors to a plane orthogonal to a surface of scanning of the beam.

Abstract: A laser printing system including a main body having a photosensitive member and an optical unit for forming an image on the photosensitive member by projecting a laser beam thereon. The optical unit is detachably provided in said main body and has a laser beam source, a laser beam source drive circuit, a laser beam shaping member, and a polygonal mirror for scanning the surface of the photosensitive member with the laser beam. The optical unit gives to the main body an instruction as to the dot density especially assigned thereto. The main body forms the image at the dot density assigned to the optical unit which is selected from a plurality of optical units having different dot densities. Accordingly, the optical units having different dot densities are prepared so as to be selectively used to obtain the desired one of the dot densities.

Abstract: An electrostatic latent image forming apparatus using a semiconductor laser forms an electrostatic latent image on a surface of a photoreceptor by a laser beam emitted from the semiconductor laser while intensity of the laser beam is lowered by a low reflectance mirror which reflects a part of the laser beam and transmits the remaining laser beam. A light absorbing layer is disposed behind the low reflectance mirror for absorbing the laser beam passing therethrough. The semiconductor laser is driven by current obtained by adding bias current to switching current and bias component out of an optical output level thereof is decreased by the low reflectance mirror. Therefore, an off-level optical output corresponding to the bias current becomes lower than that in the case in which lowering of the intensity of the laser beam is not caused, and as a result, a "fogging" phenomenon or the like can be effectively prevented.

Abstract: A laser beam scanning apparatus for beam scanning a medium with the laser beam being deflected by a deflector, comprising a first mirror provided for reflecting the laser beam after deflected by the deflector and a second mirror provided for folding a light path between the first mirror and the recording medium in relation that a first light path between the deflector and the first mirror is intersected with a second light path between the second mirror and the recording medium. The first and second mirrors are arranged so as to be movable in parallel respectively for adjusting a length of scanning line on the recording medium in a direction perpendicular to the scanning line, wherein either one of the first and second mirrors is moved when adjusting said moved mirror has lesser shift amount of the scanning line on the recording medium as compared with the other mirror.

Abstract: An electrostatic latent image forming apparatus using a semiconductor laser 11 forms an image on a surface of a photoreceptor drum 15 by a laser beam modulated by an image signal while intensity of the laser beam is lowered by a reflection mirror 16 having a reflectance as low as 30%. The semiconductor laser 11 is driven by current obtained by adding bias current Iba to switching current Isw and a bias component out of an optical output level thereof is decreased by the reflection mirror 16 having the low reflectance. Therefore, an off-level optical output correponding to the bias current becomes lower than that in the case in which lowering of the intensity of the beam is not caused, and as a result, a "fogging" phenomenon or the like can be effectively prevented.

Abstract: A laser printing system including a main body having a photosensitive member and an optical unit for forming an image on the photosensitive member by projecting a laser beam thereon. The optical unit is detachably provided in said main body and has a laser beam source, a laser beam source drive circuit, a laser beam shaping member, and a polygonal mirror for scanning the surface of the photosensitive member with the laser beam. The optical unit gives to the main body an instruction as to the dot density especially assigned thereto. The main body forms the image at the dot density assigned to the optical unit which is selected from a plurality of optical units having different dot densities. Accordingly, the optical units having different dot densities are prepared so as to be selectively used to obtain the desired one of the dot densities.